Properties added to the Player Object become Read-Only when the playSound method is used

Starting with the 26.40.2# preview cycle and extending to the latest cycle as of this reports creation date (26.40.3#), when creating new properties on the Player object and performing the playSound method on them, those properties added to the Player Object become Read-Only.

Step to reproduce:

1. Ensure content log is enabled in settings.

2. Type “!playSound” in a world to play a sound.

Expected Result:

The sound is played and the game runs as intended.

Actual Result:

The property “__temporaryProperty” becomes read-only and spams the content log.

Potential Cause:

At the start of the 26.40.2# preview cycle, the below changes occurred to the playSound method.

Moved SoundInstance class from beta to V1.2.0.

Moved SoundInstance.stop from beta to V2.9.0.

Moved Player.playSound returning a SoundInstance from beta to V1.2.0.

Moved Dimension.playSound returning a SoundInstance from beta to V1.11.0.

Link to article:https://feedback.minecraft.net/hc/en-us/articles/46333309174669-Minecraft-Beta-Preview-26-40-20#:~:text=Moved%C2%A0SoundInstance,to%C2%A0V1.11.0.